The lack of water caused by global warming is getting worse globally, and thus water purification technologies for ensuring alternative water resources have attracted attention.
Therefore, a water treatment process, which uses a reverse osmosis membrane which is a key technology for next-generation waterworks that utilize alternative water resources such as seawater desalination, water recycling, and the like, is expected to dominate industrial water markets.
Reverse osmosis membrane permeable water made by the reverse osmosis membrane becomes pure water or water very close to pure water, and used in various field such as fields related to medical sterile water, purified water for artificial dialysis, or water for manufacturing semiconductors in an electronic field.
Here, the reverse osmosis refers to a phenomenon in which a predetermined difference in water level occurs while a solution with low concentration is moved to a solution with high concentration when a predetermined period of time has passed after the two solutions having a difference in concentration are separated by a semipermeable membrane. In addition, a difference in water level occurring during this process refers to reverse osmotic pressure. An apparatus, which purifies water by allowing only water molecules to pass through the semipermeable membrane by using this principle, is referred to as a reverse osmosis facility, and the semipermeable membrane used for the reverse osmosis facility is a reverse osmosis filter module.
The reverse osmosis filter module includes a central tube, a feed spacer, a reverse osmosis (RO) membrane, and a tricot permeate water channel.
Among the components, the feed spacer serves as a passageway through which raw water is introduced. Differential pressure occurs as a flow of raw water is hindered by the feed spacer when the raw water is introduced through the feed spacer, which results in an increase in energy costs, and as a result, the lower the differential pressure, the greater the efficiency of the reverse osmosis filter module.
Meanwhile, a concentration polarization phenomenon inevitably occurs in the vicinity of the reverse osmosis membrane due to a water permeation flux, and as the concentration polarization phenomenon becomes worse, the osmotic pressure is increased in the vicinity of the reverse osmosis membrane, such that water permeability deteriorates.
In this regard, there is a need for a feed spacer capable of increasing efficiency of the reverse osmosis filter module by reducing the occurrence of differential pressure and mitigating the concentration polarization phenomenon.